Kooijman designed the minifigures with an online tool and submitted her idea to the Lego Ideas forum, which allows users to submit proposals for new Lego sets. Proposals that earn 10,000 supporters are sent to a review board and get a chance at being selected for production. (Related: "Why Is a Woman Who Loves Science So Surprising?")

The final design, pricing, and availability are still being determined, but Lego plans to release the set, which will be called Research Institute, in August 2014. Lego has faced criticism for gender stereotyping in the past, but the new set has generated excitement among female scientists.

National Geographic spoke with Kooijman via email about making Legos and science more diverse and interesting to young girls.

How did you get the idea to develop the female scientist Lego minifigures?

I have been building with Lego bricks almost all my life. I was surfing the web for inspiration and stumbled upon the Lego Ideas platform, and I was immediately excited about the concept, so I decided to post a project.

As a female scientist, I'd noticed two things about the available Lego sets: a too high male/female minifigure ratio and a rather stereotypical representation of the available female figures. It seemed logical that I would suggest a small set of female minifigures in interesting professions to make the Legos more diverse.

When did you first become interested in science?

I think I was always destined to become a scientist. I've been interested in the natural sciences since I was a young child. I happened upon geosciences and became enthusiastic about the prospect of combining physics, mathematics, and chemistry to try and understand the Earth, so I chose to pursue that.

What has your experience been as a female scientist in a mostly male profession?

It has never been a serious issue for me, personally. Most of my collaborators are men and I am the only female senior scientist in my department, but I never think about that much. Of course, there are examples of (usually older) male colleagues who have problems taking young female scientists seriously. I usually try to ignore that and let my work speak for itself.

Tell me about the process of creating the Lego set.

I first designed the set digitally using free software called Lego Digital Designer, but after I moved to Sweden from California, I got my Legos out of storage. The chemist set is currently sitting on my shelf.

How did you find out that the Lego review board approved your idea?

We set up a video conference call so they told me "in person." Recently, they admitted that they thought I was surprisingly calm about it. To that I responded that I am Northern European so I don't tend to get openly enthusiastic and I thought it would be best to act professional. Though after the call ended, I was screaming and bouncing off the walls.

What did you hope to accomplish by creating the Lego set?

It would be great if the set would get more girls interested in building with Lego bricks. It was my favorite toy as a child, and I think it has been very important in my development. If the set inspires girls to pursue careers in science and technology, that would be great too.

What has been the best reaction or feedback you've received throughout this process?

The amount of positive reactions has been absolutely overwhelming, and it has come from all over the world. One reaction in an early stage of the project was from a mother who wrote that her daughter wants to become a paleontologist and they were cheering at the screen as my project gained supporters. It is amazing when people are so enthusiastic about something you created.

Do you plan to create additional female Lego sets?

I have designed 12 female minifigure vignettes in total, and three will be in the Research Institute set. It will be up to Lego to decide if they want to produce the other vignettes as well.

It is important to note I first posted the set in spring 2012. In the last two years a lot has changed, and there have been many sets with a more balanced male/female minifigure ratio and with females in interesting roles such as a firefighter and a train engineer. I'm very happy about this, and I hope this trend will continue.